A very good place to begin at. Just two questions:
1) Centered placement of the exciter is the less compromised?
2) Rounding or damping of the corners didn't make a difference worth of consideration?
As gluing will be the fixing way, is it not better to use double sided tape on the exciter, and glue that tape instead of the exciter? Then I would be free to try other positions.
One important question: why haven't you tried the usual 1 meter panel-mic distance so it can be compared to a standard loudspeaker?
This is the exciter I plan to start with. Will probably order 4 now.
https://www.aliexpress.com/item/32683135776.html?ug_edm_item_id=32683135776&creative_img_ind=2&creative_img_tpl=154008&tracelog=rowan&rowan_id1=product_2_picture_prototype_1_pt_BR_2021-09-21&rowan_msg_id=carlCOWS_132_$ab92848a20b440e4a556dc415f342a6f&ck=in_edm_other
Click on the first box on the left.
If someone know of a better model sold by AE, please talk now.
https://www.aliexpress.com/item/32683135776.html?ug_edm_item_id=32683135776&creative_img_ind=2&creative_img_tpl=154008&tracelog=rowan&rowan_id1=product_2_picture_prototype_1_pt_BR_2021-09-21&rowan_msg_id=carlCOWS_132_$ab92848a20b440e4a556dc415f342a6f&ck=in_edm_other
Click on the first box on the left.
If someone know of a better model sold by AE, please talk now.
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I have now conducted some initial listening tests, comparing identically sized UHD EPS (rounded corners, PVA, sanding etc.) and 3mm poplar ply (similar treatment), running from about 300hz upwards. On balance, I prefer the sound of the ply panels. From my measurements, the ply panels come in about 2db less efficient than the EPS ones.
My main issue is some buzzing from the panels (both types) when running test tones, which seems to be some kind of self-generated panel noise. It's particularly obvious in the corners and sounds like distortion. It varies with frequency, some worse than others.
I'll try to record a test and post it tomorrow.
I should add that the frequency plots for the two panels are very similar. There's a bit of drop-off in the extreme treble with the ply panel, possibly due to using the 3M sticky stuff rather than gluing the exciter to the panel. I'd say the midrange is a bit fuller on the ply panel, with the top end a bit more airy on the EPS one.
My main issue is some buzzing from the panels (both types) when running test tones, which seems to be some kind of self-generated panel noise. It's particularly obvious in the corners and sounds like distortion. It varies with frequency, some worse than others.
I'll try to record a test and post it tomorrow.
I should add that the frequency plots for the two panels are very similar. There's a bit of drop-off in the extreme treble with the ply panel, possibly due to using the 3M sticky stuff rather than gluing the exciter to the panel. I'd say the midrange is a bit fuller on the ply panel, with the top end a bit more airy on the EPS one.
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Steve
565mm x 400mm
They are 3mm lightweight poplar ply, the kind I'm about to use on my canvas panel this morning. I'll be trying UHD EPS on a canvas panel too. I suspect the latter may provide the best of both worlds. I'm going to try photo mount adhesive (if the can still works). It makes for a very lightweight bond if I remember correctly.
Simon
565mm x 400mm
They are 3mm lightweight poplar ply, the kind I'm about to use on my canvas panel this morning. I'll be trying UHD EPS on a canvas panel too. I suspect the latter may provide the best of both worlds. I'm going to try photo mount adhesive (if the can still works). It makes for a very lightweight bond if I remember correctly.
Simon
Carlmart.
1) the coil on the naked panel was a test panel ,so I glued the coil in the centre to see what would happen,the response looks pretty good so as yet can't see any problems.
I did offset the exciter on the ply panel which I mounted in the centre of canvas panel , but i was thinking of mounting both centrally as the canvas absorbs the vibrations from the panel ? reducing the panel reflections ? I think?
It's worth trying just to find out what the difference is.
2) with the canvas panels I've made so far ,I've had no problems with the corners .
3) as long as the tape is up to the job of supporting your exciter I see no problem.
For short term mounting you could use G clamps to hold the spline in place and glue the exciter to the spline (or use tape) this will take all of the weight off of the exciter canvas mounting and be easily movable.
4) I have taken measurements at 1m but this is not of much use to me.
I take near field measurements to see what the panel is outputting and 3m into the room where I sit ,to see what is actually happening in the room.
1m is good for recording music as it minimises room responses ,but is not the real in room response.
Listening to the panels at 1m is very similar to wearing headphones.
Actually when listening to dml panels from directly between the panels I can't tell the difference from the headphones.
Steve.
1) the coil on the naked panel was a test panel ,so I glued the coil in the centre to see what would happen,the response looks pretty good so as yet can't see any problems.
I did offset the exciter on the ply panel which I mounted in the centre of canvas panel , but i was thinking of mounting both centrally as the canvas absorbs the vibrations from the panel ? reducing the panel reflections ? I think?
It's worth trying just to find out what the difference is.
2) with the canvas panels I've made so far ,I've had no problems with the corners .
3) as long as the tape is up to the job of supporting your exciter I see no problem.
For short term mounting you could use G clamps to hold the spline in place and glue the exciter to the spline (or use tape) this will take all of the weight off of the exciter canvas mounting and be easily movable.
4) I have taken measurements at 1m but this is not of much use to me.
I take near field measurements to see what the panel is outputting and 3m into the room where I sit ,to see what is actually happening in the room.
1m is good for recording music as it minimises room responses ,but is not the real in room response.
Listening to the panels at 1m is very similar to wearing headphones.
Actually when listening to dml panels from directly between the panels I can't tell the difference from the headphones.
Steve.
How would that be? Gluing the eps to the panel and the resonator glued to what surface?
More fun and games with exciters
The Monacor and larger Tectonic exciters both have an interesting 'feature'. The foot that typically gets stuck or glued to the panel actually screws into the main body of the exciter. As it's all plastic and very hard to actually tighten well, the whole mechanical arrangement results in horrible buzzing and distortion like sounds.
In contrast, my el cheapo £11 a pair 15 watt exciters that arrived last week show no such issues. Stuck with double sided tape to my ply plus art canvas panel, the were sounding pretty respectable. So I've made a second ply/canvas panel and glued the exciters in place, ready for testing tomorrow.
For info, these are 300x400mm triple gessoed panels from Amazon plus 100x150mm 3mm poplar ply in the centre with slightly off-centred exciter placement. The ply is glued to the canvas with 3M photo mount glue. I've also glue-gunned the canvas to the frame on the reverse to add a bit of structural integrity. I'm not sure how those staples and the canvas are going to stand up in the longer term to all the vibration.
As these exciters are cheap and light, I'm going to hold fire on a brace for the time being.
These art canvas / ply panels are, I think, going to work well. With a frequency sweep, they are free from the buzzing and rattles that have afflicted both my ply and EPS panels. Whilst the buzzing only really manifested itself with tone sweeps, it's not exactly desirable. As usual, I'm rolling them off below 300hz, handing over to my revised 15 inch OB L baffle bass (think asymmetrical U frame without the top). The latter, despite being open baffle, is flat to 40hz with a gentle roll-off below that.
The Monacor and larger Tectonic exciters both have an interesting 'feature'. The foot that typically gets stuck or glued to the panel actually screws into the main body of the exciter. As it's all plastic and very hard to actually tighten well, the whole mechanical arrangement results in horrible buzzing and distortion like sounds.
In contrast, my el cheapo £11 a pair 15 watt exciters that arrived last week show no such issues. Stuck with double sided tape to my ply plus art canvas panel, the were sounding pretty respectable. So I've made a second ply/canvas panel and glued the exciters in place, ready for testing tomorrow.
For info, these are 300x400mm triple gessoed panels from Amazon plus 100x150mm 3mm poplar ply in the centre with slightly off-centred exciter placement. The ply is glued to the canvas with 3M photo mount glue. I've also glue-gunned the canvas to the frame on the reverse to add a bit of structural integrity. I'm not sure how those staples and the canvas are going to stand up in the longer term to all the vibration.
As these exciters are cheap and light, I'm going to hold fire on a brace for the time being.
These art canvas / ply panels are, I think, going to work well. With a frequency sweep, they are free from the buzzing and rattles that have afflicted both my ply and EPS panels. Whilst the buzzing only really manifested itself with tone sweeps, it's not exactly desirable. As usual, I'm rolling them off below 300hz, handing over to my revised 15 inch OB L baffle bass (think asymmetrical U frame without the top). The latter, despite being open baffle, is flat to 40hz with a gentle roll-off below that.
My latest recording post of the epoxy xps panel is on page 380 post 3795 .
I think the Don Juan recording is very nice ,lots of detail .
Please us good quality sounding headphones,for best results, very important !
I will eventually cut these panels in half and see how they perform in a smaller size.
Steve.
I think the Don Juan recording is very nice ,lots of detail .
Please us good quality sounding headphones,for best results, very important !
I will eventually cut these panels in half and see how they perform in a smaller size.
Steve.
A tale of two exciter fixings
I have now compared the frequency sweeps of two different exciter mountings on my art canvas / ply panels. In the attached image, the blue line is using double sided silicone type tape, and the orange line is where the exciter is glued to the 10x15cm plywood.
EQing the tape version is tricky due to the double trough. The glued version, on the other hand needs a little work between 300 and 3000hz, a broad boost between 3khz and 13khz and finally some extreme treble lift.
The second image shows the frequency sweep with EQ and also an LR24 high pass crossover @ 300hz. Extreme HF is a tad down, but not bad at all. This of course gets me thinking about whether using UHD EPS instead of the 3mm ply on the art canvas panel may give just a bit more HF extension. Only one way to find out I suppose...
I have now compared the frequency sweeps of two different exciter mountings on my art canvas / ply panels. In the attached image, the blue line is using double sided silicone type tape, and the orange line is where the exciter is glued to the 10x15cm plywood.
EQing the tape version is tricky due to the double trough. The glued version, on the other hand needs a little work between 300 and 3000hz, a broad boost between 3khz and 13khz and finally some extreme treble lift.
The second image shows the frequency sweep with EQ and also an LR24 high pass crossover @ 300hz. Extreme HF is a tad down, but not bad at all. This of course gets me thinking about whether using UHD EPS instead of the 3mm ply on the art canvas panel may give just a bit more HF extension. Only one way to find out I suppose...
Attachments
pixel1.
i only ever use one exciter per panel.
the size of the panel at the moment is 60cm x86cm ,the exiter is my usual 10watt 25mm coil.
i have had to move the microphones closer to the panels(2.5ft) as my room is so full of boxes, from floor to ceiling which are affecting the sound quality .
i hope it sounds ok?
i thought you had the 50-100 watt exciters ?
steve.
i only ever use one exciter per panel.
the size of the panel at the moment is 60cm x86cm ,the exiter is my usual 10watt 25mm coil.
i have had to move the microphones closer to the panels(2.5ft) as my room is so full of boxes, from floor to ceiling which are affecting the sound quality .
i hope it sounds ok?
i thought you had the 50-100 watt exciters ?
steve.
yes in fact I had bought the 50 w ones but to tell the truth I did not like them, certainly never tried with good panels but I have had commitments in recent months and I have not dedicated time.But I am always interested in this technology even if it is actually abandoned from famous brands, tectonic itself does not seem to be very committed to promoting their DML products, it seems to have been abandoned for at least 2 year
AS you can see here, Aiyima makes several models, but none of them stands more than 20 or 25 watts.
2pcs 44MM Resonant Horn 8Ohm 10W Portable Audio Vibration Mini Speaker For Home Theater DIY Modification Loudspeakers|Connectors| - AliExpress
2pcs 44MM Resonant Horn 8Ohm 10W Portable Audio Vibration Mini Speaker For Home Theater DIY Modification Loudspeakers|Connectors| - AliExpress